1
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Flores M, Goodrich DW. Retinoblastoma Protein Paralogs and Tumor Suppression. Front Genet 2022; 13:818719. [PMID: 35368709 PMCID: PMC8971665 DOI: 10.3389/fgene.2022.818719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/25/2022] [Indexed: 01/01/2023] Open
Abstract
The retinoblastoma susceptibility gene (RB1) is the first tumor suppressor gene discovered and a prototype for understanding regulatory networks that function in opposition to oncogenic stimuli. More than 3 decades of research has firmly established a widespread and prominent role for RB1 in human cancer. Yet, this gene encodes but one of three structurally and functionally related proteins that comprise the pocket protein family. A central question in the field is whether the additional genes in this family, RBL1 and RBL2, are important tumor suppressor genes. If so, how does their tumor suppressor activity overlap or differ from RB1. Here we revisit these questions by reviewing relevant data from human cancer genome sequencing studies that have been rapidly accumulating in recent years as well as pertinent functional studies in genetically engineered mice. We conclude that RBL1 and RBL2 do have important tumor suppressor activity in some contexts, but RB1 remains the dominant tumor suppressor in the family. Given their similarities, we speculate on why RB1 tumor suppressor activity is unique.
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Affiliation(s)
| | - David W. Goodrich
- Roswell Park Comprehensive Cancer Center, Department of Pharmacology and Therapeutics, Buffalo, NY, United States
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2
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Reprogramming of H3K9bhb at regulatory elements is a key feature of fasting in the small intestine. Cell Rep 2021; 37:110044. [PMID: 34818540 PMCID: PMC8668154 DOI: 10.1016/j.celrep.2021.110044] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/31/2021] [Accepted: 11/01/2021] [Indexed: 12/25/2022] Open
Abstract
β-hydroxybutyrate (β-OHB) is an essential metabolic energy source during fasting and functions as a chromatin regulator by lysine β-hydroxybutyrylation (Kbhb) modification of the core histones H3 and H4. We report that Kbhb on histone H3 (H3K9bhb) is enriched at proximal promoters of critical gene subsets associated with lipolytic and ketogenic metabolic pathways in small intestine (SI) crypts during fasting. Similar Kbhb enrichment is observed in Lgr5+ stem cell-enriched epithelial spheroids treated with β-OHB in vitro. Combinatorial chromatin state analysis reveals that H3K9bhb is associated with active chromatin states and that fasting enriches for an H3K9bhb-H3K27ac signature at active metabolic gene promoters and distal enhancer elements. Intestinal knockout of Hmgcs2 results in marked loss of H3K9bhb-associated loci, suggesting that local production of β-OHB is responsible for chromatin reprogramming within the SI crypt. We conclude that modulation of H3K9bhb in SI crypts is a key gene regulatory event in response to fasting. Terranova et al. demonstrate that fasting induces production of HMGCS2 and β-hydroxybutyrate in small intestine (SI) crypt cells. This causes enrichment of H3K9bhb within regulatory regions of critical metabolic genes in crypt epithelial cells. Loss of intestinal Hmgcs2 impairs H3K9bhb enrichment and affects expression of H3K9bhb-associated metabolic gene programs.
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3
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Li Q, Zhou K, Du D, Chen Y, Liu D, Guan X. Dynamic expression of FAM83D in peripheral organs at different ages in mice. Gene Expr Patterns 2021; 41:119199. [PMID: 34325035 DOI: 10.1016/j.gep.2021.119199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/01/2021] [Accepted: 07/24/2021] [Indexed: 10/20/2022]
Abstract
The family with sequence similarity 83 member (FAM83D) plays important role in the process of cell division as well as tumour progression. However, the role of FAM83D in tissue development was not well explored. Here, we assessed transcriptional levels of FAM83D and other possibly related genes in organs of mice at different ages and methylation level of FAM83D promoter. Our results indicate the trend of FAM83D expression in mouse testis, liver, lung and small intestine, and its relationship to CYCLINB1 and KI67. Finally, we found no effect of promoter methylation status on FAM83D expression during mice development.
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Affiliation(s)
- Qixian Li
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Kaicheng Zhou
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Demin Du
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yali Chen
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Dekang Liu
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China.
| | - Xiaowei Guan
- Department of Human Anatomy and Histoembryology, Nanjing University of Chinese Medicine, Nanjing, China.
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4
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Onufer EJ, Aladegbami B, Imai T, Seiler K, Bajinting A, Courtney C, Sutton S, Bustos A, Yao J, Yeh CH, Sescleifer A, Wang LV, Guo J, Warner BW. EGFR in enterocytes & endothelium and HIF1α in enterocytes are dispensable for massive small bowel resection induced angiogenesis. PLoS One 2020; 15:e0236964. [PMID: 32931498 PMCID: PMC7491746 DOI: 10.1371/journal.pone.0236964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/16/2020] [Indexed: 12/15/2022] Open
Abstract
Background Short bowel syndrome (SBS) results from significant loss of small intestinal length. In response to this loss, adaptation occurs, with Epidermal Growth Factor Receptor (EGFR) being a key driver. Besides enhanced enterocyte proliferation, we have revealed that adaptation is associated with angiogenesis. Further, we have found that small bowel resection (SBR) is associated with diminished oxygen delivery and elevated levels of hypoxia-inducible factor 1-alpha (HIF1α). Methods We ablated EGFR in the epithelium and endothelium as well as HIF1α in the epithelium, ostensibly the most hypoxic element. Using these mice, we determined the effects of these genetic manipulations on intestinal blood flow after SBR using photoacoustic microscopy (PAM), intestinal adaptation and angiogenic responses. Then, given that endothelial cells require a stromal support cell for efficient vascularization, we ablated EGFR expression in intestinal subepithelial myofibroblasts (ISEMFs) to determine its effects on angiogenesis in a microfluidic model of human small intestine. Results Despite immediate increased demand in oxygen extraction fraction measured by PAM in all mouse lines, were no differences in enterocyte and endothelial cell EGFR knockouts or enterocyte HIF1α knockouts by POD3. Submucosal capillary density was also unchanged by POD7 in all mouse lines. Additionally, EGFR silencing in ISEMFs did not impact vascular network development in a microfluidic device of human small intestine. Conclusions Overall, despite the importance of EGFR in facilitating intestinal adaptation after SBR, it had no impact on angiogenesis in three cell types–enterocytes, endothelial cells, and ISEMFs. Epithelial ablation of HIF1α also had no impact on angiogenesis in the setting of SBS.
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Affiliation(s)
- Emily J. Onufer
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Bola Aladegbami
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Toru Imai
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America
- Department of Electrical Engineering, Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, Pasadena, CA, United States of America
| | - Kristen Seiler
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Adam Bajinting
- Saint Louis University School of Medicine, St. Louis, MO, United States of America
| | - Cathleen Courtney
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Stephanie Sutton
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Aiza Bustos
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Junjie Yao
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America
| | - Cheng-Hung Yeh
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America
| | - Anne Sescleifer
- Saint Louis University School of Medicine, St. Louis, MO, United States of America
| | - Lihong V. Wang
- Department of Electrical Engineering, Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, Pasadena, CA, United States of America
| | - Jun Guo
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
| | - Brad W. Warner
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children’s Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, United States of America
- * E-mail:
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5
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Serum deprivation initiates adaptation and survival to oxidative stress in prostate cancer cells. Sci Rep 2020; 10:12505. [PMID: 32719369 PMCID: PMC7385110 DOI: 10.1038/s41598-020-68668-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 06/22/2020] [Indexed: 02/08/2023] Open
Abstract
Inadequate nutrient intake leads to oxidative stress disrupting homeostasis, activating signaling, and altering metabolism. Oxidative stress serves as a hallmark in developing prostate lesions, and an aggressive cancer phenotype activating mechanisms allowing cancer cells to adapt and survive. It is unclear how adaptation and survival are facilitated; however, literature across several organisms demonstrates that a reversible cellular growth arrest and the transcription factor, nuclear factor-kappaB (NF-κB), contribute to cancer cell survival and therapeutic resistance under oxidative stress. We examined adaptability and survival to oxidative stress following nutrient deprivation in three prostate cancer models displaying varying degrees of tumorigenicity. We observed that reducing serum (starved) induced reactive oxygen species which provided an early oxidative stress environment and allowed cells to confer adaptability to increased oxidative stress (H2O2). Measurement of cell viability demonstrated a low death profile in stressed cells (starved + H2O2), while cell proliferation was stagnant. Quantitative measurement of apoptosis showed no significant cell death in stressed cells suggesting an adaptive mechanism to tolerate oxidative stress. Stressed cells also presented a quiescent phenotype, correlating with NF-κB nuclear translocation, suggesting a mechanism of tolerance. Our data suggests that nutrient deprivation primes prostate cancer cells for adaptability to oxidative stress and/or a general survival mechanism to anti-tumorigenic agents.
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6
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Compensation between Wnt-driven tumorigenesis and cellular responses to ribosome biogenesis inhibition in the murine intestinal epithelium. Cell Death Differ 2020; 27:2872-2887. [PMID: 32355182 DOI: 10.1038/s41418-020-0548-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 12/21/2022] Open
Abstract
Ribosome biogenesis inhibition causes cell cycle arrest and apoptosis through the activation of tumor suppressor-dependent surveillance pathways. These responses are exacerbated in cancer cells, suggesting that targeting ribosome synthesis may be beneficial to patients. Here, we characterize the effect of the loss-of-function of Notchless (Nle), an essential actor of ribosome biogenesis, on the intestinal epithelium undergoing tumor initiation due to acute Apc loss-of-function. We show that ribosome biogenesis dysfunction strongly alleviates Wnt-driven tumor initiation by restoring cell cycle exit and differentiation in Apc-deficient progenitors. Conversely Wnt hyperactivation attenuates the cellular responses to surveillance pathways activation induced by ribosome biogenesis dysfunction, as proliferation was maintained at control-like levels in the stem cells and progenitors of double mutants. Thus, our data indicate that, while ribosome biogenesis inhibition efficiently reduces cancer cell proliferation in the intestinal epithelium, enhanced resistance of Apc-deficient stem and progenitor cells to ribosome biogenesis defects may be an important concern when using a therapeutic strategy targeting ribosome production for the treatment of Wnt-dependent tumorigenesis.
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7
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Spliceosome protein Eftud2 promotes colitis-associated tumorigenesis by modulating inflammatory response of macrophage. Mucosal Immunol 2019; 12:1164-1173. [PMID: 31278373 DOI: 10.1038/s41385-019-0184-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 02/04/2023]
Abstract
Alternative splicing (AS) of mRNA is known to be involved in regulation of immune cell differentiation and activation. Elongation factor Tu GTP binding domain containing 2 (Eftud2) is an AS factor to potentially modulate innate immune response in macrophages. In this study, we investigate its involvement in the pathogenesis of colitis-associated cancer (CAC). Using an established mouse model of CAC, we show that Eftud2 is constantly overexpressed in the colonic tissues as well as infiltrating macrophages. Myeloid-specific knockout of Eftud2 remarkably suppresses chronic intestinal inflammation and tumorigenesis, which is associated with decreased production of inflammatory cytokines and tumorigenic factors. Repression of colonic inflammation and colorectal tumor development in Eftud2-deficient mice is due to the impaired activation of NF-κB signaling in LPS-challenged macrophages. Furthermore, the alteration of Eftud2-mediated AS involving the components of TLR4-NF-κB cascades underlies the impairment of NF-κB activation. Overall, these findings provide new insights into the tight link between inflammation and cancer and modulation of AS in innate immune signals may be a potentially therapeutic avenue for CAC treatment.
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8
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Cheng CW, Biton M, Haber AL, Gunduz N, Eng G, Gaynor LT, Tripathi S, Calibasi-Kocal G, Rickelt S, Butty VL, Moreno M, Iqbal AM, Bauer-Rowe KE, Imada S, Ulutas MS, Mylonas C, Whary MT, Levine SS, Basbinar Y, Hynes RO, Mino-Kenudson M, Deshpande V, Boyer LA, Fox JG, Terranova C, Rai K, Piwnica-Worms H, Mihaylova MM, Regev A, Yilmaz ÖH. Ketone Body Signaling Mediates Intestinal Stem Cell Homeostasis and Adaptation to Diet. Cell 2019; 178:1115-1131.e15. [PMID: 31442404 PMCID: PMC6732196 DOI: 10.1016/j.cell.2019.07.048] [Citation(s) in RCA: 210] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 06/03/2019] [Accepted: 07/25/2019] [Indexed: 01/18/2023]
Abstract
Little is known about how metabolites couple tissue-specific stem cell function with physiology. Here we show that, in the mammalian small intestine, the expression of Hmgcs2 (3-hydroxy-3-methylglutaryl-CoA synthetase 2), the gene encoding the rate-limiting enzyme in the production of ketone bodies, including beta-hydroxybutyrate (βOHB), distinguishes self-renewing Lgr5+ stem cells (ISCs) from differentiated cell types. Hmgcs2 loss depletes βOHB levels in Lgr5+ ISCs and skews their differentiation toward secretory cell fates, which can be rescued by exogenous βOHB and class I histone deacetylase (HDAC) inhibitor treatment. Mechanistically, βOHB acts by inhibiting HDACs to reinforce Notch signaling, instructing ISC self-renewal and lineage decisions. Notably, although a high-fat ketogenic diet elevates ISC function and post-injury regeneration through βOHB-mediated Notch signaling, a glucose-supplemented diet has the opposite effects. These findings reveal how control of βOHB-activated signaling in ISCs by diet helps to fine-tune stem cell adaptation in homeostasis and injury.
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Affiliation(s)
- Chia-Wei Cheng
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA
| | - Moshe Biton
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA,Klarman Cell Observatory, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA,These authors contributed equally to this work
| | - Adam L. Haber
- Klarman Cell Observatory, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA,These authors contributed equally to this work
| | - Nuray Gunduz
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey 06800
| | - George Eng
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Liam T. Gaynor
- Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston MA, 02215, USA
| | - Surya Tripathi
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA
| | - Gizem Calibasi-Kocal
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Dokuz Eylul University, Institute of Oncology, Department of Translational Oncology, Izmir, Turkey
| | - Steffen Rickelt
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA
| | - Vincent L. Butty
- BioMicro Center, at MIT, Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
| | - Marta Moreno
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA
| | - Ameena M Iqbal
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA
| | | | - Shinya Imada
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Department of Gastroenterological and Transplant Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University,1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Mehmet Sefa Ulutas
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Department of Biology, Siirt University, Science and Arts Faculty, 56100 Siirt, Turkey
| | | | - Mark T. Whary
- Division of Comparative Medicine, Department of Biological Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Stuart S. Levine
- BioMicro Center, at MIT, Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
| | - Yasemin Basbinar
- Dokuz Eylul University, Institute of Oncology, Department of Translational Oncology, Izmir, Turkey
| | - Richard O. Hynes
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Howard Hughes Medical Institute, Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
| | - Mari Mino-Kenudson
- Department of Pathology, Massachusetts General Hospital Boston and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Vikram Deshpande
- Department of Pathology, Massachusetts General Hospital Boston and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Laurie A. Boyer
- Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
| | - James G. Fox
- Division of Comparative Medicine, Department of Biological Engineering, MIT, Cambridge, Massachusetts 02139, USA
| | - Christopher Terranova
- Genomic Medicine Department, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Kunal Rai
- Genomic Medicine Department, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Helen Piwnica-Worms
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Maria M. Mihaylova
- The Ohio State Comprehensive Cancer Center, Department of Biological Chemistry and Pharmacology, Ohio State University, 308 Wiseman Hall, Columbus, OH 43210, USA
| | - Aviv Regev
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA,Klarman Cell Observatory, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
| | - Ömer H. Yilmaz
- Koch Institute for Integrative Cancer Research at MIT, Massachusetts 02139, USA,Department of Biology, MIT, Cambridge, Massachusetts 02139, USA,Department of Pathology, Massachusetts General Hospital Boston and Harvard Medical School, Boston, Massachusetts 02114, USA,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA,Klarman Cell Observatory, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA,Lead Contact,Correspondence: Ömer H. Yilmaz () (Ö.H.Y)
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9
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Caspases interplay with kinases and phosphatases to determine cell fate. Eur J Pharmacol 2019; 855:20-29. [DOI: 10.1016/j.ejphar.2019.04.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 04/05/2019] [Accepted: 04/29/2019] [Indexed: 12/15/2022]
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10
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Goupille O, Kadri Z, Langelé A, Luccantoni S, Badoual C, Leboulch P, Chrétien S. The integrity of the FOG-2 LXCXE pRb-binding motif is required for small intestine homeostasis. Exp Physiol 2019; 104:1074-1089. [PMID: 31012180 DOI: 10.1113/ep087369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 04/16/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do Fog2Rb- / Rb- mice present a defect of small intestine homeostasis? What is the main finding and its importance? The importance of interactions between FOG-2 and pRb in adipose tissue physiology has previously been demonstrated. Here it is shown that this interaction is also intrinsic to small intestine homeostasis and exerts extrinsic control over mouse metabolism. Thus, this association is involved in maintaining small intestine morphology, and regulating crypt proliferation and lineage differentiation. It therefore affects mouse growth and adaptation to a high-fat diet. ABSTRACT GATA transcription factors and their FOG cofactors play a key role in tissue-specific development and differentiation, from worms to humans. We have shown that GATA-1 and FOG-2 contain an LXCXE pRb-binding motif. Interactions between retinoblastoma protein (pRb) and GATA-1 are crucial for erythroid proliferation and differentiation, whereas the LXCXE pRb-binding site of FOG-2 is involved in adipogenesis. Fog2-knock-in mice have defective pRb binding and are resistant to obesity, due to efficient white-into-brown fat conversion. Our aim was to investigate the pathophysiological impact of FOG-2-pRb interaction on the small intestine and mouse growth. Histological analysis of the small intestine revealed architectural changes in Fog2Rb- / Rb- mice, including villus shortening, with crypt expansion and a change in muscularis propria thickness. These differences were more marked in the proximo-distal part of the small intestine and were associated with an increase in crypt cell proliferation and disruption of the goblet and Paneth cell lineage. The small intestine of the mutants was unable to adapt to a high-fat diet, and had significantly lower plasma lipid levels on such a diet. Fog2Rb- / Rb- mice displayed higher levels of glucose-dependent insulinotropic peptide release, and lower levels of insulin-like growth factor I release on a regular diet. Their intestinal lipid absorption was impaired, resulting in restricted weight gain. In addition to the intrinsic effects of the mutation on adipose tissue, we show here an extrinsic relationship between the intestine and the effect of FOG-2 mutation on mouse metabolism. In conclusion, the interaction of FOG-2 with pRb coordinates the crypt-villus axis and controls small intestine homeostasis.
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Affiliation(s)
- Olivier Goupille
- Division of Innovative Therapies, UMR E007, Institute of Biology François Jacob, CEA, Université Paris Sud, Université Paris-Saclay, Fontenay aux Roses, France
| | - Zahra Kadri
- Division of Innovative Therapies, UMR E007, Institute of Biology François Jacob, CEA, Université Paris Sud, Université Paris-Saclay, Fontenay aux Roses, France
| | - Amandine Langelé
- Division of Innovative Therapies, UMR E007, Institute of Biology François Jacob, CEA, Université Paris Sud, Université Paris-Saclay, Fontenay aux Roses, France
| | - Sophie Luccantoni
- Immunology of Viral Infections and Autoimmune Diseases, IDMIT Department, Institute of Biology François Jacob, CEA - Université Paris Sud 11 - INSERM U1184, Fontenay-aux-Roses, France
| | - Cécile Badoual
- Department of Pathology, G. Pompidou European Hospital APHP - Université Paris, Descartes, Paris, France
| | - Philippe Leboulch
- Division of Innovative Therapies, UMR E007, Institute of Biology François Jacob, CEA, Université Paris Sud, Université Paris-Saclay, Fontenay aux Roses, France.,Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.,Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Stany Chrétien
- Division of Innovative Therapies, UMR E007, Institute of Biology François Jacob, CEA, Université Paris Sud, Université Paris-Saclay, Fontenay aux Roses, France.,INSERM, Paris, France
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11
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Hinze C, Boucrot E. Endocytosis in proliferating, quiescent and terminally differentiated cells. J Cell Sci 2018; 131:131/23/jcs216804. [PMID: 30504135 DOI: 10.1242/jcs.216804] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Endocytosis mediates nutrient uptake, receptor internalization and the regulation of cell signaling. It is also hijacked by many bacteria, viruses and toxins to mediate their cellular entry. Several endocytic routes exist in parallel, fulfilling different functions. Most studies on endocytosis have used transformed cells in culture. However, as the majority of cells in an adult body have exited the cell cycle, our understanding is biased towards proliferating cells. Here, we review the evidence for the different pathways of endocytosis not only in dividing, but also in quiescent, senescent and terminally differentiated cells. During mitosis, residual endocytosis is dedicated to the internalization of caveolae and specific receptors. In non-dividing cells, clathrin-mediated endocytosis (CME) functions, but the activity of alternative processes, such as caveolae, macropinocytosis and clathrin-independent routes, vary widely depending on cell types and functions. Endocytosis supports the quiescent state by either upregulating cell cycle arrest pathways or downregulating mitogen-induced signaling, thereby inhibiting cell proliferation. Endocytosis in terminally differentiated cells, such as skeletal muscles, adipocytes, kidney podocytes and neurons, supports tissue-specific functions. Finally, uptake is downregulated in senescent cells, making them insensitive to proliferative stimuli by growth factors. Future studies should reveal the molecular basis for the differences in activities between the different cell states.
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Affiliation(s)
- Claudia Hinze
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Emmanuel Boucrot
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK .,Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London WC1E 7HX, UK
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12
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Onufer EJ, Tay S, Barron LK, Courtney CM, Warner BW, Guo J. Intestinal epithelial cell-specific Raptor is essential for high fat diet-induced weight gain in mice. Biochem Biophys Res Commun 2018; 505:1174-1179. [PMID: 30318117 DOI: 10.1016/j.bbrc.2018.10.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 11/30/2022]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) is a major regulator of cell growth and proliferation through fuel sensing. Systemic inhibition of mTOR as well as manipulation of its downstream products prevent diet-induced obesity. The purpose of this study was to determine the consequences of intestine-targeted mTORC1 inhibition. To attenuate intestinal mTORC1 activity, Villin-CreER mice were crossed with Raptorflox/flox mice, creating an intestinal-specific Raptor null line (i-Raptor -/-). Mice were fed a high fat diet (HFD) and compositional changes as well as food intake levels were assessed. Over a five-week time course, i-Raptor -/- mice consistently gained less body weight on a HFD compared to wildtype (WT) mice secondary to significantly reduced food intake. Importantly, the i-Raptor -/- mice did not appear to be malnourished, demonstrated by their preservation of lean body mass. i-Raptor -/- mice also maintained a normal metabolic profile without significant changes in triglyceride or fasting glucose levels. Further investigation revealed that GDF-15 mRNA expression was significantly enhanced in i-Raptor -/- enterocytes when refed with HFD after overnight starvation. In summary, our study establishes that loss of intestinal specific-mTORC1 is protective of the development of diet-induced obesity by reducing food intake without altering the metabolic profile.
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Affiliation(s)
- Emily J Onufer
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Shirli Tay
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Lauren K Barron
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Cathleen M Courtney
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Brad W Warner
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Jun Guo
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA.
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Abstract
Cellular quiescence is a reversible mode of cell cycle exit that allows cells and organisms to withstand unfavorable stress conditions. The factors that underlie the entry, exit, and maintenance of the quiescent state are crucial for understanding normal tissue development and function as well as pathological conditions such as chronic wound healing and cancer. In vitro models of quiescence have been used to understand the factors that contribute to quiescence under well-controlled experimental conditions. Here, we describe an in vitro model of quiescence that is based on neonatal human dermal fibroblasts. The fibroblasts are induced into quiescence by antiproliferative signals, contact inhibition, and serum-starvation (mitogen withdrawal). We describe the isolation of fibroblasts from skin, methods for inducing quiescence in isolated fibroblasts, and approaches to manipulate the fibroblasts in proliferating and quiescent states to determine critical regulators of quiescence.
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14
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Aladegbami B, Barron L, Bao J, Colasanti J, Erwin CR, Warner BW, Guo J. Epithelial cell specific Raptor is required for initiation of type 2 mucosal immunity in small intestine. Sci Rep 2017; 7:5580. [PMID: 28717211 PMCID: PMC5514129 DOI: 10.1038/s41598-017-06070-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/07/2017] [Indexed: 12/13/2022] Open
Abstract
Intestinal tuft cells are one of 4 secretory cell linages in the small intestine and the source of IL-25, a critical initiator of the type 2 immune response to parasite infection. When Raptor, a critical scaffold protein for mammalian target of rapamycin complex 1 (mTORC1), was acutely deleted in intestinal epithelium via Tamoxifen injection in Tritrichomonas muris (Tm) infected mice, tuft cells, IL-25 in epithelium and IL-13 in the mesenchyme were significantly reduced, but Tm burden was not affected. When Tm infected mice were treated with rapamycin, DCLK1 and IL-25 expression in enterocytes and IL-13 expression in mesenchyme were diminished. After massive small bowel resection, tuft cells and Tm were diminished due to the diet used postoperatively. The elimination of Tm and subsequent re-infection of mice with Tm led to type 2 immune response only in WT, but Tm colonization in both WT and Raptor deficient mice. When intestinal organoids were stimulated with IL-4, tuft cells and IL-25 were induced in both WT and Raptor deficient organoids. In summary, our study reveals that enterocyte specific Raptor is required for initiating a type 2 immune response which appears to function through the regulation of mTORC1 activity.
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Affiliation(s)
- Bola Aladegbami
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Lauren Barron
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - James Bao
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Jason Colasanti
- Fischell Department of Bioengineering in the A. James Clark School of Engineering at the University of Maryland, College Park, MD, 20742, USA
| | - Christopher R Erwin
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Brad W Warner
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jun Guo
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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15
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Sun RC, Choi PM, Diaz-Miron JL, Sommovilla J, Guo J, Erwin CR, Warner BW. Epithelial IGF1R is dispensable for IGF2 mediated enhanced intestinal adaptation in retinoblastoma-deficient mice. J Pediatr Surg 2017; 52:1026-1030. [PMID: 28343662 PMCID: PMC5466888 DOI: 10.1016/j.jpedsurg.2017.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/09/2017] [Indexed: 11/26/2022]
Abstract
PURPOSE Previously, we demonstrated enhanced adaptation after small bowel resection (SBR) in intestinal-specific retinoblastoma (Rb)-deficient mice along with elevated levels of insulin-like growth factor 2 (IGF2) expression within the villi. The purpose of this study was to verify that the insulin-like growth factor 1 receptor (IGF1R) plays a role in this phenomenon. METHODS Inducible and intestinal specific Rb and IGF1R double knockout mice (iRb/IGF1R-IKO) (n=4) and Rb single knockout mice (iRb-IKO) (n=5) underwent 50% mid SBR. On post-operative day 28, mice were harvested, and structural adaptation was measured as changes in crypt depth and villus height. Rates of enterocyte proliferation were recorded. IGF2 expression within the remnant villi was measured via RT-PCR. RESULTS Both iRb-IKO and iRb/IGF1R-IKO mice demonstrated enhanced adaptation with at least a 45% increase in both crypt depth and villus height in the proximal and distal remnant bowel. Both groups showed elevation of IGF2 expression in the remnant villi, but there were no differences between the two groups. CONCLUSION Epithelial IGF1R is dispensable for IGF2-mediated enhanced intestinal adaptation in retinoblastoma-deficient mice. Our findings suggest that IGF2 signals for enhanced adaptation in cells outside of the epithelium. Further investigation is needed to study the IGF2/IGF1R signaling interaction within the mesenchyme. LEVEL OF EVIDENCE Animal study - not clinical.
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16
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Barron LK, Bao JW, Aladegbami BG, Colasanti JJ, Guo J, Erwin CR, Warner BW. Toll-like receptor 4 is critical for the development of resection-associated hepatic steatosis. J Pediatr Surg 2017; 52:1014-1019. [PMID: 28351520 PMCID: PMC5466889 DOI: 10.1016/j.jpedsurg.2017.03.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 03/09/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND A significant number of children with short bowel syndrome experience intestinal failure-associated liver disease. We recently demonstrated accelerated hepatic steatosis after 50% small bowel resection (SBR) in mice. Since SBR is associated with alterations in the gut microbiome, the purpose of this study was to determine whether TLR4 signaling is critical to the development of resection-associated hepatic steatosis. METHODS Male C57BL6 (control) and TLR4-knockout (KO) mice underwent 50% proximal SBR. Liver sections were analyzed to obtain the percent lipid content, and Ileal sections were assessed for morphological adaptation. Intestinal TLR4 mRNA expression was measured at 7days and 10weeks. RESULTS Compared to controls, TLR4 KO mice demonstrated similar weight gain and morphological adaptation after SBR. Hepatic steatosis was decreased 32-fold in the absence of TLR4. Intestinal TLR4 mRNA expression was significantly elevated 7days after SBR. We also found that TLR4 expression in the intestine was 20-fold higher in whole bowel sections compared with isolated enterocytes. CONCLUSIONS TLR4 signaling is critical for the development of resection-associated steatosis, but not involved in intestinal adaptation after massive SBR. Further studies are needed to delineate the mechanism for TLR4 signaling in the genesis of resection-associated liver injury. LEVEL OF EVIDENCE Animal study, not clinical.
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Affiliation(s)
- Lauren K Barron
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - James W Bao
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - Bola G Aladegbami
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - Jason J Colasanti
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - Jun Guo
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - Christopher R Erwin
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA
| | - Brad W Warner
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; St. Louis Children's Hospital, St. Louis, MO, USA.
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17
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Thompson CA, Wojta K, Pulakanti K, Rao S, Dawson P, Battle MA. GATA4 Is Sufficient to Establish Jejunal Versus Ileal Identity in the Small Intestine. Cell Mol Gastroenterol Hepatol 2017; 3:422-446. [PMID: 28462382 PMCID: PMC5404030 DOI: 10.1016/j.jcmgh.2016.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 12/29/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS Patterning of the small intestinal epithelium along its cephalocaudal axis establishes three functionally distinct regions: duodenum, jejunum, and ileum. Efficient nutrient assimilation and growth depend on the proper spatial patterning of specialized digestive and absorptive functions performed by duodenal, jejunal, and ileal enterocytes. When enterocyte function is disrupted by disease or injury, intestinal failure can occur. One approach to alleviate intestinal failure would be to restore lost enterocyte functions. The molecular mechanisms determining regionally defined enterocyte functions, however, are poorly delineated. We previously showed that GATA binding protein 4 (GATA4) is essential to define jejunal enterocytes. The goal of this study was to test the hypothesis that GATA4 is sufficient to confer jejunal identity within the intestinal epithelium. METHODS To test this hypothesis, we generated a novel Gata4 conditional knock-in mouse line and expressed GATA4 in the ileum, where it is absent. RESULTS We found that GATA4-expressing ileum lost ileal identity. The global gene expression profile of GATA4-expressing ileal epithelium aligned more closely with jejunum and duodenum rather than ileum. Focusing on jejunal vs ileal identity, we defined sets of jejunal and ileal genes likely to be regulated directly by GATA4 to suppress ileal identity and promote jejunal identity. Furthermore, our study implicates GATA4 as a transcriptional repressor of fibroblast growth factor 15 (Fgf15), which encodes an enterokine that has been implicated in an increasing number of human diseases. CONCLUSIONS Overall, this study refines our understanding of an important GATA4-dependent molecular mechanism to pattern the intestinal epithelium along its cephalocaudal axis by elaborating on GATA4's function as a crucial dominant molecular determinant of jejunal enterocyte identity. Microarray data from this study have been deposited into NCBI Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo) and are accessible through GEO series accession number GSE75870.
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Key Words
- Cyp7a1, cytochrome P450 family 7 subfamily A member 1
- E, embryonic day
- EMSA, electrophoretic mobility shift assay
- Enterohepatic Signaling
- FXR
- FXR, farnesoid X receptor
- Fabp6, fatty acid binding protein 6
- Fgf, fibroblast growth factor
- Fgf15
- Jejunal Identity
- OSTα/β, organic solute transporter α/β
- PCR, polymerase chain reaction
- SBS, short-bowel syndrome
- Slc, solute carrier
- TSS, transcription start site
- Transcriptional Regulation
- bio-ChIP-seq, biotin-mediated chromatin immunoprecipitation with high-throughput sequencing
- bp, base pair
- cDNA, complementary DNA
- cKI, conditional knock-in
- cKO, conditional knockout
- dATP, deoxyadenosine triphosphate
- lnl, loxP-flanked PGK-Neo-3xSV40 polyadenylation sequence
- mRNA, messenger RNA
- pA, polyadenylation
- qRT, quantitative reverse-transcription
- xiFABP, Xenopus I-FABP
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Affiliation(s)
- Cayla A. Thompson
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Kevin Wojta
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Kirthi Pulakanti
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin
| | - Sridhar Rao
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
- Division of Pediatric Hematology, Oncology, and Blood and Marrow Transplant, Medical College of Wisconsin, Milwaukee, Wisconsin
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin
| | - Paul Dawson
- Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Michele A. Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
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18
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Barron L, Sun RC, Aladegbami B, Erwin CR, Warner BW, Guo J. Intestinal Epithelial-Specific mTORC1 Activation Enhances Intestinal Adaptation After Small Bowel Resection. Cell Mol Gastroenterol Hepatol 2016; 3:231-244. [PMID: 28275690 PMCID: PMC5331783 DOI: 10.1016/j.jcmgh.2016.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/18/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND & AIMS Intestinal adaptation is a compensatory response to the massive loss of small intestine after surgical resection. We investigated the role of intestinal epithelial cell-specific mammalian target of rapamycin complex 1 (i-mTORC1) in intestinal adaptation after massive small bowel resection (SBR). METHODS We performed 50% proximal SBR on mice to study adaptation. To manipulate i-mTORC1 activity, Villin-CreER transgenic mice were crossed with tuberous sclerosis complex (TSC)1flox/flox or Raptorflox/flox mice to inducibly activate or inactivate i-mTORC1 activity with tamoxifen. Western blot was used to confirm the activity of mTORC1. Crypt depth and villus height were measured to score adaptation. Immunohistochemistry was used to investigate differentiation and rates of crypt proliferation. RESULTS After SBR, mice treated with systemic rapamycin showed diminished structural adaptation, blunted crypt cell proliferation, and significant body weight loss. Activating i-mTORC1 via TSC1 deletion induced larger hyperproliferative crypts and disorganized Paneth cells without a significant change in villus height. After SBR, ablating TSC1 in intestinal epithelium induced a robust villus growth with much stronger crypt cell proliferation, but similar body weight recovery. Acute inactivation of i-mTORC1 through deletion of Raptor did not change crypt cell proliferation or mucosa structure, but significantly reduced lysozyme/matrix metalloproteinase-7-positive Paneth cell and goblet cell numbers, with increased enteroendocrine cells. Surprisingly, ablation of intestinal epithelial cell-specific Raptor after SBR did not affect adaptation or crypt proliferation, but dramatically reduced body weight recovery after surgery. CONCLUSIONS Systemic, but not intestinal-specific, mTORC1 is important for normal adaptation responses to SBR. Although not required, forced enterocyte mTORC1 signaling after resection causes an enhanced adaptive response.
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Key Words
- Differentiation
- EGF, epidermal growth factor
- IHC, immunohistochemistry
- MMP, matrix metalloproteinase
- PCR, polymerase chain reaction
- Raptor
- S6K, S6 kinase
- SBR, small bowel resection
- TAM, tamoxifen
- TSC, tuberous sclerosis complex
- TSC1
- WT, wild type
- i-TSC-/-, intestinal epithelial cell–specific tuberous sclerosis complex 1 null mice
- mTOR, mammalian target of rapamycin
- mTORC, mammalian target of rapamycin complex
- p-HH3, phosphorylated histone H3
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Affiliation(s)
| | | | | | | | | | - Jun Guo
- Correspondence Address correspondence to: Jun Guo, PhD, BJC Institute of Health Room 7118, 425 South Euclid Avenue, St. Louis, Missouri 63110. fax: (314) 747–0610.BJC Institute of Health Room 7118425 South Euclid AvenueSt. LouisMissouri 63110
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19
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Wei L, Leibowitz BJ, Wang X, Epperly M, Greenberger J, Zhang L, Yu J. Inhibition of CDK4/6 protects against radiation-induced intestinal injury in mice. J Clin Invest 2016; 126:4076-4087. [PMID: 27701148 DOI: 10.1172/jci88410] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy causes dose-limiting toxicity and long-term complications in rapidly renewing tissues, including the gastrointestinal tract. Currently, there is no FDA-approved agent for the prevention or treatment of radiation-induced intestinal injury. In this study, we have shown that PD 0332991 (PD), an FDA-approved selective inhibitor of cyclin-dependent kinase 4/6 (CDK4/6), prevents radiation-induced lethal intestinal injury in mice. Treating mice with PD or a structurally distinct CDK4/6 inhibitor prior to radiation blocked proliferation and crypt apoptosis and improved crypt regeneration. PD treatment also enhanced LGR5+ stem cell survival and regeneration after radiation. PD was an on-target inhibitor of RB phosphorylation and blocked G1/S transition in the intestinal crypts. PD treatment strongly but reversibly inhibited radiation-induced p53 activation, which blocked p53-upregulated modulator of apoptosis-dependent (PUMA-dependent) apoptosis without affecting p21-dependent suppression of DNA damage accumulation, with a repair bias toward nonhomologous end joining. Further, deletion of PUMA synergized with PD treatment for even greater intestinal radioprotection. Our results demonstrate that the cell cycle critically regulates the DNA damage response and survival of intestinal stem cells and support the concept that pharmacological quiescence is a potentially highly effective and selective strategy for intestinal radioprotection.
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20
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Barron LK, Gayer CP, Roberts A, Golden JM, Aladegbami BG, Guo J, Erwin CR, Warner BW. Liver steatosis induced by small bowel resection is prevented by oral vancomycin. Surgery 2016; 160:1485-1495. [PMID: 27592213 DOI: 10.1016/j.surg.2016.07.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/16/2016] [Accepted: 07/07/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Intestinal failure-associated liver disease causes significant mortality in patients with short bowel syndrome. Steatosis, a major component of intestinal failure-associated liver disease has been shown to persist even after weaning from parenteral nutrition. We sought to determine whether steatosis occurs in our murine model of short bowel syndrome and whether steatosis was affected by manipulation of the intestinal microbiome. METHODS Male C57BL6 mice underwent 50% small bowel resection and orogastric gavage with vancomycin or vehicle for 10 weeks. DNA was extracted from stool samples then sequenced using 16s rRNA. Liver lipid content was analyzed. Bile acids were measured in liver and stool. RESULTS Compared with unoperated mice, small bowel resection resulted in significant changes in the fecal microbiome and was associated with a >25-fold increase in steatosis. Oral vancomycin profoundly altered the gut microbiome and was associated with a 15-fold reduction in hepatic lipid content after resection. There was a 17-fold reduction in fecal secondary bile acids after vancomycin treatment. CONCLUSION Massive small bowel resection in mice is associated with development of steatosis and prevented by oral vancomycin. These findings implicate a critical role for gut bacteria in intestinal failure-associated liver disease pathogenesis and illuminate a novel, operative model for future investigation into this important morbidity.
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Affiliation(s)
- Lauren K Barron
- Department Of Surgery, Washington University in St. Louis, St. Louis, MO; Division of Pediatric Surgery, St. Louis Children's Hospital, St. Louis, MO
| | - Christopher P Gayer
- Keck School of Medicine, University of Southern California, Los Angeles, CA; Division of Pediatric Surgery, Children's Hospital Los Angeles, Los Angeles, CA
| | - Anne Roberts
- Division of Pediatric Surgery, Children's Hospital Los Angeles, Los Angeles, CA
| | - Jamie M Golden
- Division of Pediatric Surgery, Children's Hospital Los Angeles, Los Angeles, CA
| | - Bola G Aladegbami
- Department Of Surgery, Washington University in St. Louis, St. Louis, MO; Division of Pediatric Surgery, St. Louis Children's Hospital, St. Louis, MO
| | - Jun Guo
- Division of Pediatric Surgery, St. Louis Children's Hospital, St. Louis, MO
| | | | - Brad W Warner
- Department Of Surgery, Washington University in St. Louis, St. Louis, MO; Division of Pediatric Surgery, St. Louis Children's Hospital, St. Louis, MO.
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21
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He Y, Schmidt MA, Erwin C, Guo J, Sun R, Pendarvis K, Warner BW, Herman EM. Transgenic Soybean Production of Bioactive Human Epidermal Growth Factor (EGF). PLoS One 2016; 11:e0157034. [PMID: 27314851 PMCID: PMC4912142 DOI: 10.1371/journal.pone.0157034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/24/2016] [Indexed: 12/16/2022] Open
Abstract
Necrotizing enterocolitis (NEC) is a devastating condition of premature infants that results from the gut microbiome invading immature intestinal tissues. This results in a life-threatening disease that is frequently treated with the surgical removal of diseased and dead tissues. Epidermal growth factor (EGF), typically found in bodily fluids, such as amniotic fluid, salvia and mother's breast milk, is an intestinotrophic growth factor and may reduce the onset of NEC in premature infants. We have produced human EGF in soybean seeds to levels biologically relevant and demonstrated its comparable activity to commercially available EGF. Transgenic soybean seeds expressing a seed-specific codon optimized gene encoding of the human EGF protein with an added ER signal tag at the N' terminal were produced. Seven independent lines were grown to homozygous and found to accumulate a range of 6.7 +/- 3.1 to 129.0 +/- 36.7 μg EGF/g of dry soybean seed. Proteomic and immunoblot analysis indicates that the inserted EGF is the same as the human EGF protein. Phosphorylation and immunohistochemical assays on the EGF receptor in HeLa cells indicate the EGF protein produced in soybean seed is bioactive and comparable to commercially available human EGF. This work demonstrates the feasibility of using soybean seeds as a biofactory to produce therapeutic agents in a soymilk delivery platform.
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Affiliation(s)
- Yonghua He
- School of Plant Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Monica A. Schmidt
- School of Plant Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Christopher Erwin
- St. Louis Children's Hospital and Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jun Guo
- St. Louis Children's Hospital and Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Raphael Sun
- St. Louis Children's Hospital and Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Ken Pendarvis
- School of Animal & Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Brad W. Warner
- St. Louis Children's Hospital and Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Eliot M. Herman
- School of Plant Sciences, University of Arizona, Tucson, Arizona, United States of America
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22
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Warner BW. The Pathogenesis of Resection-Associated Intestinal Adaptation. Cell Mol Gastroenterol Hepatol 2016; 2:429-438. [PMID: 27722191 PMCID: PMC5042605 DOI: 10.1016/j.jcmgh.2016.05.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/06/2016] [Indexed: 12/14/2022]
Abstract
After massive small-bowel resection, the remnant bowel compensates by a process termed adaptation. Adaptation is characterized by villus elongation and crypt deepening, which increases the capacity for absorption and digestion per unit length. The mechanisms/mediators of this important response are multiple. The purpose of this review is to highlight the major basic contributions in elucidating a more comprehensive understanding of this process.
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Affiliation(s)
- Brad W. Warner
- Correspondence Address correspondence to: Brad W. Warner, MD, Washington University School of Medicine, St. Louis Children's Hospital, One Children's Place, Suite 5s40, St. Louis, Missouri 63110. fax: (314) 454-2442.Washington University School of MedicineSt. Louis Children's HospitalOne Children's PlaceSuite 5s40St. LouisMissouri 63110
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23
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Fasting protects mice from lethal DNA damage by promoting small intestinal epithelial stem cell survival. Proc Natl Acad Sci U S A 2015; 112:E7148-54. [PMID: 26644583 DOI: 10.1073/pnas.1509249112] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Short-term fasting protects mice from lethal doses of chemotherapy through undetermined mechanisms. Herein, we demonstrate that fasting preserves small intestinal (SI) architecture by maintaining SI stem cell viability and SI barrier function following exposure to high-dose etoposide. Nearly all SI stem cells were lost in fed mice, whereas fasting promoted sufficient SI stem cell survival to preserve SI integrity after etoposide treatment. Lineage tracing demonstrated that multiple SI stem cell populations, marked by Lgr5, Bmi1, or HopX expression, contributed to fasting-induced survival. DNA repair and DNA damage response genes were elevated in SI stem/progenitor cells of fasted etoposide-treated mice, which importantly correlated with faster resolution of DNA double-strand breaks and less apoptosis. Thus, fasting preserved SI stem cell viability as well as SI architecture and barrier function suggesting that fasting may reduce host toxicity in patients undergoing dose intensive chemotherapy.
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Ribosome biogenesis dysfunction leads to p53-mediated apoptosis and goblet cell differentiation of mouse intestinal stem/progenitor cells. Cell Death Differ 2015; 22:1865-76. [PMID: 26068591 DOI: 10.1038/cdd.2015.57] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 03/31/2015] [Accepted: 04/13/2015] [Indexed: 02/07/2023] Open
Abstract
Ribosome biogenesis is an essential cellular process. Its impairment is associated with developmental defects and increased risk of cancer. The in vivo cellular responses to defective ribosome biogenesis and the underlying molecular mechanisms are still incompletely understood. In particular, the consequences of impaired ribosome biogenesis within the intestinal epithelium in mammals have not been investigated so far. Here we adopted a genetic approach to investigate the role of Notchless (NLE), an essential actor of ribosome biogenesis, in the adult mouse intestinal lineage. Nle deficiency led to defects in the synthesis of large ribosomal subunit in crypts cells and resulted in the rapid elimination of intestinal stem cells and progenitors through distinct types of cellular responses, including apoptosis, cell cycle arrest and biased differentiation toward the goblet cell lineage. Similar observations were made using the rRNA transcription inhibitor CX-5461 on intestinal organoids culture. Importantly, we found that p53 activation was responsible for most of the cellular responses observed, including differentiation toward the goblet cell lineage. Moreover, we identify the goblet cell-specific marker Muc2 as a direct transcriptional target of p53. Nle-deficient ISCs and progenitors disappearance persisted in the absence of p53, underlying the existence of p53-independent cellular responses following defective ribosome biogenesis. Our data indicate that NLE is a crucial factor for intestinal homeostasis and provide new insights into how perturbations of ribosome biogenesis impact on cell fate decisions within the intestinal epithelium.
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25
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Both epidermal growth factor and insulin-like growth factor receptors are dispensable for structural intestinal adaptation. J Pediatr Surg 2015; 50:943-7. [PMID: 25818318 PMCID: PMC4439349 DOI: 10.1016/j.jpedsurg.2015.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 03/10/2015] [Indexed: 12/31/2022]
Abstract
PURPOSE Intestinal adaptation structurally represents increases in crypt depth and villus height in response to small bowel resection (SBR). Previously, we found that neither epidermal growth factor receptor (EGFR) nor insulin-like growth factor 1 receptor (IGF1R) function was individually required for normal adaptation. In this study, we sought to determine the effect of disrupting both EGFR and IGF1R expression on resection-induced adaptation. METHODS Intestinal-specific EGFR and IGF1R double knockout mice (EGFR/IGF1R-IKO) (n=6) and wild-type (WT) control mice (n=7) underwent 50% proximal SBR. On postoperative day (POD) 7, structural adaptation was scored by measuring crypt depth and villus height. Rates of crypt cell proliferation, apoptosis, and submucosal capillary density were also compared. RESULTS After 50% SBR, normal adaptation occurred in both WT and EGFR/IGF1R-IKO. Rates of proliferation and apoptosis were no different between the two groups. The angiogenic response was less in the EGFR/IGF1R-IKO compared to WT mice. CONCLUSION Disrupted expression of EGFR and IGF1R in the intestinal epithelial cells does not affect resection-induced structural adaptation but attenuates angiogenesis after SBR. These findings suggest that villus growth is driven by receptors and pathways that occur outside the epithelial cell component, while angiogenic responses may be influenced by epithelial-endothelial crosstalk.
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Diaz-Miron J, Sun R, Choi P, Sommovilla J, Guo J, Erwin CR, Mei J, Scott Worthen G, Warner BW. The effect of impaired angiogenesis on intestinal function following massive small bowel resection. J Pediatr Surg 2015; 50:948-53. [PMID: 25818317 PMCID: PMC4439276 DOI: 10.1016/j.jpedsurg.2015.03.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 03/10/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE Intestinal adaptation involves villus lengthening, crypt deepening, and increased capillary density following small bowel resection (SBR). Mice lacking the proangiogenic chemokine CXCL5 have normal structural adaptation but impaired angiogenesis. This work evaluates the impact of incomplete adaptive angiogenesis on the functional capacity of the intestine after SBR. METHODS CXCL5 knockout (KO) and C57BL/6 wild-type (WT) mice underwent 50% SBR. Magnetic resonance imaging measured weekly body composition. Intestinal absorptive capacity was evaluated through fecal fat analysis. Gene expression profiles for select macronutrient transporters were measured via RT-PCR. Postoperative crypt and villus measurements were assessed for structural adaptation. Submucosal capillary density was measured through CD31 immunohistochemistry. RESULTS Comparable postoperative weight gain occurred initially. Diminished weight gain, impaired fat absorption, and elevated steatorrhea occurred in KO mice after instituting high-fat diet. Greater postoperative upregulation of ABCA1 fat transporter occurred in WT mice, while PEPT1 protein transporter was significantly downregulated in KO mice. KO mice had impaired angiogenesis but intact structural adaptation. CONCLUSION After SBR, KO mice display an inefficient intestinal absorption profile with perturbed macronutrient transporter expression, impaired fat absorption, and slower postoperative weight gain. In addition to longer villi and deeper crypts, an intact angiogenic response may be required to achieve functional adaptation to SBR.
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Affiliation(s)
- Jose Diaz-Miron
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Raphael Sun
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Pamela Choi
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Joshua Sommovilla
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Jun Guo
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Christopher R Erwin
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Junjie Mei
- Division of Neonatology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - G Scott Worthen
- Division of Neonatology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Brad W Warner
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO.
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High-protein diet improves postoperative weight gain after massive small-bowel resection. J Gastrointest Surg 2015; 19:451-7. [PMID: 25519080 PMCID: PMC4965231 DOI: 10.1007/s11605-014-2715-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/21/2014] [Indexed: 01/31/2023]
Abstract
INTRODUCTION Short bowel syndrome (SBS) is a morbid clinical condition that results from massive small-bowel resection (SBR). After SBR, there is a dramatic weight loss in the acute postoperative period. Our aim was to determine the impact of a high-protein diet (HPD) on weight gain and body composition in mice after SBR. METHODS C57BL/6 mice underwent 50 % proximal SBR. Postoperatively, mice were randomly selected to receive standard rodent liquid diet (LD) (n = 6) or an isocaloric HPD (n = 9) for 28 days. Mice weights were recorded daily. Body composition analyses were obtained weekly. Student's t test was used for statistical comparisons with p < 0.05 considered significant. RESULTS Mice that were fed HPD after SBR returned to baseline weight on average at postoperative day (POD) 8 versus mice that were fed LD that returned to baseline weight on average at POD 22. Total fat mass and lean mass were significantly greater by POD 14 within the HPD group. Both groups of mice demonstrated normal structural adaptation. CONCLUSION HPD results in greater weight gain and improved body composition in mice after SBR. This finding may be clinically important for patients with SBS since improved weight gain may reduce the time needed for parenteral nutrition.
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Tarang S, Doi SMSR, Gurumurthy CB, Harms D, Quadros R, Rocha-Sanchez SM. Generation of a Retinoblastoma (Rb)1-inducible dominant-negative (DN) mouse model. Front Cell Neurosci 2015; 9:52. [PMID: 25755634 PMCID: PMC4337335 DOI: 10.3389/fncel.2015.00052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 02/03/2015] [Indexed: 11/13/2022] Open
Abstract
Retinoblastoma 1 (Rb1) is an essential gene regulating cellular proliferation, differentiation, and homeostasis. To exert these functions, Rb1 is recruited and physically interacts with a growing variety of signaling pathways. While Rb1 does not appear to be ubiquitously expressed, its expression has been confirmed in a variety of hematopoietic and neuronal-derived cells, including the inner ear hair cells (HCs). Studies in transgenic mice demonstrate that complete germline or conditional Rb1 deletion leads to abnormal cell proliferation, followed by massive apoptosis; making it difficult to fully address Rb1's biochemical activities. To overcome these limitations, we developed a tetracycline-inducible TetO-CB-myc6-Rb1 (CBRb) mouse model to achieve transient and inducible dominant-negative (DN) inhibition of the endogenous RB1 protein. Our strategy involved fusing the Rb1 gene to the lysosomal protease pre-procathepsin B (CB), thus allowing for further routing of the DN-CBRb fusion protein and its interacting complexes for proteolytic degradation. Moreover, reversibility of the system is achieved upon suppression of doxycycline (Dox) administration. Preliminary characterization of DN-CBRb mice bred to a ubiquitous rtTA mouse line demonstrated a significant inhibition of the endogenous RB1 protein in the inner ear and in a number of other organs where RB1 is expressed. Examination of the postnatal (P) DN-CBRb mice inner ear at P10 and P28 showed the presence of supernumerary inner HCs (IHCs) in the lower turns of the cochleae, which corresponds to the described expression domain of the endogenous Rb1 gene. Selective and reversible suppression of gene expression is both an experimental tool for defining function and a potential means to medical therapy. Given the limitations associated with Rb1-null mice lethality, this model provides a valuable resource for understanding RB1 activity, relative contribution to HC regeneration and its potential therapeutic application.
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Affiliation(s)
- Shikha Tarang
- Department of Oral Biology, Creighton University School of Dentistry Omaha, NE,USA
| | - Songila M S R Doi
- Department of Oral Biology, Creighton University School of Dentistry Omaha, NE,USA
| | - Channabasavaiah B Gurumurthy
- Mouse Genome Engineering Core Facility, Department of Genetics Cell Biology and Anatomy, University of Nebraska Medical Center Omaha, NE, USA
| | - Donald Harms
- Mouse Genome Engineering Core Facility, Department of Genetics Cell Biology and Anatomy, University of Nebraska Medical Center Omaha, NE, USA
| | - Rolen Quadros
- Mouse Genome Engineering Core Facility, Department of Genetics Cell Biology and Anatomy, University of Nebraska Medical Center Omaha, NE, USA
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Choi PM, Sun RC, Sommovilla J, Diaz-Miron J, Guo J, Erwin CR, Warner BW. IGF-2 is necessary for retinoblastoma-mediated enhanced adaptation after small-bowel resection. J Gastrointest Surg 2014; 18:1887-93. [PMID: 25002022 PMCID: PMC4201888 DOI: 10.1007/s11605-014-2586-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/24/2014] [Indexed: 01/31/2023]
Abstract
Previously, we have demonstrated that genetically disrupting retinoblastoma protein (Rb) expression in enterocytes results in taller villi, mimicking resection-induced adaption responses. Rb deficiency also results in elevated insulin-like growth factor-2 (IGF-2) expression in villus enterocytes. We propose that postoperative disruption of Rb results in enhanced adaptation which is driven by IGF-2. Inducible, intestine-specific Rb-null mice (iRbIKO) and wild-type (WT) littermates underwent a 50% proximal small-bowel resection (SBR) at 7-9 weeks of age. They were then given tamoxifen on postoperative days (PODs) 4-6 and harvested on POD 28. The experiment was then repeated on double knockouts of both IGF-2 and Rb (IGF-2 null/iRbIKO). iRbIKO mice demonstrated enhanced resection-induced adaptive villus growth after SBR and increased IGF-2 messenger RNA (mRNA) in ileal villus enterocytes compared to their WT littermates. In the IGF-2 null/iRbIKO double-knockout mice, there was no additional villus growth beyond what was expected of normal resection-induced adaptation. Adult mice in which Rb is inducibly deleted from the intestinal epithelium following SBR have augmented adaptive growth. IGF-2 expression is necessary for enhanced adaptation associated with acute intestinal Rb deficiency.
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Affiliation(s)
- Pamela M Choi
- Division of Pediatric Surgery, Department of Surgery, St Louis Children's Hospital, Washington University School of Medicine, One Children's Place, Suite 5S40, St Louis, MO, 63110, USA
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Neutrophil infiltration favors colitis-associated tumorigenesis by activating the interleukin-1 (IL-1)/IL-6 axis. Mucosal Immunol 2014; 7:1106-15. [PMID: 24424523 DOI: 10.1038/mi.2013.126] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 12/18/2013] [Indexed: 02/04/2023]
Abstract
Neutrophil infiltration is a key event in chronic intestinal inflammation and associated colorectal cancer, but how these cells support cancer development is poorly understood. In this study, using a mouse model of colitis-associated cancer (CAC), we have demonstrated that infiltrated neutrophils produce large amounts of interleukin-1 (IL)-1β that is critical for the development of CAC. Depletion of neutrophil or blockade of IL-1β activity significantly reduced mucosal damage and tumor formation. This protumorigenic function of IL-1β was mainly attributed to increased IL-6 secretion by intestine-resident mononuclear phagocytes (MPs). Furthermore, commensal flora-derived lipopolysaccharide (LPS) was identified to trigger IL-1β expression in neutrophils. Importantly, accumulation of IL-1β-expressing neutrophils was seen in lesions of patients suffering from ulceratic CAC and these infiltrated neutrophils induced IL-6 production by intestinal MPs in an IL-1β-dependent manner. Overall, these findings reveal that in CAC milieu, infiltrating neutrophils secrete IL-1β that promotes tumorigenesis by inducing IL-6 production by intestinal MPs.
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31
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Walker EM, Thompson CA, Battle MA. GATA4 and GATA6 regulate intestinal epithelial cytodifferentiation during development. Dev Biol 2014; 392:283-94. [PMID: 24929016 PMCID: PMC4149467 DOI: 10.1016/j.ydbio.2014.05.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/06/2014] [Accepted: 05/21/2014] [Indexed: 11/18/2022]
Abstract
The intestinal epithelium performs vital roles in organ function by absorbing nutrients and providing a protective barrier. The zinc-finger containing transcription factors GATA4 and GATA6 regulate enterocyte gene expression and control regional epithelial cell identity in the adult intestinal epithelium. Although GATA4 and GATA6 are expressed in the developing intestine, loss of either factor alone during the period of epithelial morphogenesis and cytodifferentiation fails to disrupt these processes. Therefore, we tested the hypothesis that GATA4 and GATA6 function redundantly to control these aspects of intestinal development. We used Villin-Cre, which deletes specifically in the intestinal epithelium during the period of villus development and epithelial cytodifferentiation, to generate Gata4Gata6 double conditional knockout embryos. Mice lacking GATA4 and GATA6 in the intestinal epithelium died within 24h of birth. At E18.5, intestinal villus architecture and epithelial cell populations were altered. Enterocytes were lost, and goblet cells were increased. Proliferation was also increased in GATA4-GATA6 deficient intestinal epithelium. Although villus morphology appeared normal at E16.5, the first time at which both Gata4 and Gata6 were efficiently reduced, changes in expression of markers of enterocytes, goblet cells, and proliferative cells were detected. Moreover, goblet cell number was increased at E16.5. Expression of the Notch ligand Dll1 and the Notch target Olfm4 were reduced in mutant tissue indicating decreased Notch signaling. Finally, we found that GATA4 occupies chromatin near the Dll1 transcription start site suggesting direct regulation of Dll1 by GATA4. We demonstrate that GATA4 and GATA6 play an essential role in maintaining proper intestinal epithelial structure and in regulating intestinal epithelial cytodifferentiation. Our data highlight a novel role for GATA factors in fine tuning Notch signaling during intestinal epithelial development to repress goblet cell differentiation.
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Affiliation(s)
- Emily M Walker
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA
| | - Cayla A Thompson
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA
| | - Michele A Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA.
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Sáenz Robles MT, Chong JL, Koivisto C, Trimboli A, Liu H, Leone G, Pipas JM. Viral oncogene expression in the stem/progenitor cell compartment of the mouse intestine induces adenomatous polyps. Mol Cancer Res 2014; 12:1355-64. [PMID: 24994749 DOI: 10.1158/1541-7786.mcr-14-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
UNLABELLED Genetic and epigenetic events that alter gene expression and/or protein function or localization are thought to be the primary mechanism that drives tumorigenesis and governs the clinical behavior of cancers. Yet, a number of studies have shown that the effects of oncogene expression or tumor suppressor ablation are highly dependent on cell type. The molecular basis for this cell-type specificity and how it contributes to tumorigenesis are unknown. Here, expression of a truncated SV40 large T antigen in murine intestinal crypts promoted the formation of numerous adenomatous polyps in the colon and small intestine. In contrast, when the same T-antigen construct is expressed in villous enterocytes, the consequences are limited to hyperplasia and dysplasia. The T-antigen-induced polyps show high levels of the proto-oncogene c-Myc protein even though there is no transport of β-catenin to the nucleus. Targeting the expression of viral oncogenes to intestinal crypts or villi provides a murine model system for studying cell-type specific effects in tumorigenesis, and is particularly relevant to the study of APC/β-catenin-independent pathways contributing to the generation of intestinal polyps. IMPLICATIONS This mouse model system describes the formation of colon polyps in the absence of Wnt/β-catenin signaling.
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Affiliation(s)
| | - Jean Leon Chong
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Christopher Koivisto
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Anthony Trimboli
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Huayang Liu
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - Gustavo Leone
- Department of Human Genetics and Cancer Center, Ohio State University, Columbus, Ohio
| | - James M Pipas
- Department of Biological Sciences, University of Pittsburgh. Pittsburgh, Pennsylvania.
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33
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Sun RC, Choi PM, Guo J, Erwin CR, Warner BW. Insulin-like growth factor 2 and its enterocyte receptor are not required for adaptation in response to massive small bowel resection. J Pediatr Surg 2014; 49:966-70; discussion 970. [PMID: 24888844 PMCID: PMC4044537 DOI: 10.1016/j.jpedsurg.2014.01.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 01/27/2014] [Indexed: 12/20/2022]
Abstract
PURPOSE Enhanced structural features of resection-induced intestinal adaptation have been demonstrated following the administration of multiple different growth factors and peptides. Among these, the insulin-like growth factor (IGF) system has been considered to be significant. In this study, we employ mutant mouse strains to directly test the contribution of IGF2 and its enterocyte receptor (IGF1R) toward the adaptation response to massive small bowel resection (SBR). METHODS IGF2-knockout (IGF2-KO) (n=8) and intestine specific IGF1R-knockout mice (IGF1R-IKO) (n=9) and their wild type (WT) littermates (n=5, n=7, respectively) underwent 50% proximal SBR. At post-operative day 7, structural adaptation was measured as crypt depth and villus height. Rates of enterocyte proliferation and apoptosis were also recorded. RESULTS The successful deletion of IGF2 and IGF1R expression in the enterocytes was confirmed by RT-PCR and Western blot, respectively. Normal adaptation occurred in both IGF2-KO and IGF1R-IKO mice after 50% SBR. Post-operative rates of proliferation and apoptosis in both IGF2-KO and IGF1R-IKO mice were no different than their respective controls. CONCLUSION IGF2 and functional IGF1R signaling in enterocytes are both dispensable for resection-induced adaptation responses. The mechanism for IGF-stimulation of intestinal adaptation may involve other ligands or cellular compartments within the intestine.
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MESH Headings
- Adaptation, Physiological
- Animals
- Apoptosis
- Blotting, Western
- Cell Proliferation
- Disease Models, Animal
- Enterocytes/metabolism
- Enterocytes/pathology
- Gene Expression Regulation
- Insulin-Like Growth Factor II/biosynthesis
- Insulin-Like Growth Factor II/genetics
- Intestinal Mucosa
- Intestine, Small/metabolism
- Intestine, Small/pathology
- Intestine, Small/surgery
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- RNA/genetics
- Receptor, IGF Type 1/biosynthesis
- Receptor, IGF Type 1/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Short Bowel Syndrome/genetics
- Short Bowel Syndrome/metabolism
- Short Bowel Syndrome/pathology
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Affiliation(s)
- Raphael C Sun
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pamela M Choi
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jun Guo
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christopher R Erwin
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brad W Warner
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Choi PM, Guo J, Erwin CR, Wandu WS, Leinicke JA, Xie Y, Davidson NO, Warner BW. Disruption of retinoblastoma protein expression in the intestinal epithelium impairs lipid absorption. Am J Physiol Gastrointest Liver Physiol 2014; 306:G909-15. [PMID: 24742992 PMCID: PMC4024723 DOI: 10.1152/ajpgi.00067.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 04/07/2014] [Indexed: 01/31/2023]
Abstract
We previously demonstrated increased villus height following genetic deletion, or knockout, of retinoblastoma protein (Rb) in the intestinal epithelium (Rb-IKO). Here we determined the functional consequences of augmented mucosal growth on intestinal fat absorption and following a 50% small bowel resection (SBR). Mice with constitutively disrupted Rb expression in the intestinal epithelium (Rb-IKO) along with their floxed (wild-type, WT) littermates were placed on a high-fat diet (HFD, 42% kcal fat) for 54 wk. Mice were weighed weekly, and fat absorption, indirect calorimetry, and MRI body composition were measured. Rb-IKO mice were also subjected to a 50% SBR, followed by HFD feeding for 33 wk. In separate experiments, we examined intestinal fat absorption in mice with conditional (tamoxifen-inducible) intestinal Rb (inducible Rb-IKO) deletion. Microarray revealed that the transcriptional expression of lipid absorption/transport genes was significantly reduced in constitutive Rb-IKO mice. These mice demonstrated greater mucosal surface area yet manifested paradoxically impaired intestinal long-chain triglyceride absorption and decreased cholesterol absorption. Despite attenuated lipid absorption, there were no differences in metabolic rate, body composition, and weight gain in Rb-IKO and WT mice at baseline and following SBR. We also confirmed fat malabsorption in inducible Rb-IKO mice. We concluded that, despite an expanded mucosal surface area, Rb-IKO mice demonstrate impaired lipid absorption without compensatory alterations in energy homeostasis or body composition. These findings underscore the importance of delineating structural/functional relationships in the gut and suggest a previously unknown role for Rb in the regulation of intestinal lipid absorption.
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Affiliation(s)
- Pamela M Choi
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Jun Guo
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Christopher R Erwin
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Wambui S Wandu
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer A Leinicke
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Yan Xie
- Department of Gastroenterology, Washington University School of Medicine, St. Louis, Missouri
| | - Nicholas O Davidson
- Department of Gastroenterology, Washington University School of Medicine, St. Louis, Missouri
| | - Brad W Warner
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri;
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Lapierre M, Bonnet S, Bascoul-Mollevi C, Ait-Arsa I, Jalaguier S, Del Rio M, Plateroti M, Roepman P, Ychou M, Pannequin J, Hollande F, Parker M, Cavailles V. RIP140 increases APC expression and controls intestinal homeostasis and tumorigenesis. J Clin Invest 2014; 124:1899-913. [PMID: 24667635 DOI: 10.1172/jci65178] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 01/23/2014] [Indexed: 12/14/2022] Open
Abstract
Deregulation of the Wnt/APC/β-catenin signaling pathway is an important consequence of tumor suppressor APC dysfunction. Genetic and molecular data have established that disruption of this pathway contributes to the development of colorectal cancer. Here, we demonstrate that the transcriptional coregulator RIP140 regulates intestinal homeostasis and tumorigenesis. Using Rip140-null mice and mice overexpressing human RIP140, we found that RIP140 inhibited intestinal epithelial cell proliferation and apoptosis. Interestingly, following whole-body irradiation, mice lacking RIP140 exhibited improved regenerative capacity in the intestine, while mice overexpressing RIP140 displayed reduced recovery. Enhanced RIP140 expression strongly repressed human colon cancer cell proliferation in vitro and after grafting onto nude mice. Moreover, in murine tissues and human cancer cells, RIP140 stimulated APC transcription and inhibited β-catenin activation and target gene expression. Finally, RIP140 mRNA and RIP140 protein levels were decreased in human colon cancers compared with those in normal mucosal tissue, and low levels of RIP140 expression in adenocarcinomas from patients correlated with poor prognosis. Together, these results support a tumor suppressor role for RIP140 in colon cancer.
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36
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Choi PM, Sun RC, Sommovilla J, Diaz-Miron J, Khil J, Erwin CR, Guo J, Warner BW. The role of enteral fat as a modulator of body composition after small bowel resection. Surgery 2014; 156:412-8. [PMID: 24713095 DOI: 10.1016/j.surg.2014.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 03/09/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND After massive small bowel resection (SBR), a postoperative diet high in fat is associated with enhanced villus growth. The purpose of this study was to further elucidate the quantity and composition of enteral fat in structural and metabolic changes after SBR. METHODS C57/Bl6 mice underwent a 50% proximal SBR. Mice were then randomized to receive a low-fat diet (12% kcal fat), medium-fat diet (44% kcal fat), or high-fat diet (HFD; 71% kcal fat) ad libitum. In a separate experiment, mice underwent 50% proximal SBR and then were randomized to liquid diets of 42% kcal of fat in which the fat was composed of menhaden oil, milk fat, or olive oil. After 2 weeks, mice underwent body composition analysis and the small intestine was harvested. RESULTS Mice that ingested the greatest amount of enteral fat (HFD) had the greatest percent lean mass. When the effects of the different kinds of enteral fat were analyzed, mice that consumed menhaden oil had the greatest percent lean mass with the greatest overall retention of preoperative weight. CONCLUSION These findings suggest that enteral fat enriched in omega-3 fatty acids may offer clinically relevant metabolic advantages for patients with short gut syndrome.
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Affiliation(s)
- Pamela M Choi
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Raphael C Sun
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Joshua Sommovilla
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Jose Diaz-Miron
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Jaclyn Khil
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Christopher R Erwin
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Jun Guo
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO
| | - Brad W Warner
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO.
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High-fat diet enhances villus growth during the adaptation response to massive proximal small bowel resection. J Gastrointest Surg 2014; 18:286-94; discussion 294. [PMID: 24002772 PMCID: PMC4409787 DOI: 10.1007/s11605-013-2338-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 08/20/2013] [Indexed: 01/31/2023]
Abstract
Previous studies have shown that high-fat diet (HFD) enhances adaptation if provided immediately following small bowel resection (SBR). The purpose of this study was to determine if HFD could further enhance villus growth after resection-induced adaptation had already taken place. C57/Bl6 mice underwent a 50 % proximal SBR or sham operation and were then provided a standard rodent liquid diet (LD) ad lib. After a typical period of adaptation (7 days), SBR and sham-operated mice were randomized to receive either LD or HFD (42 % kcal fat) for an additional 7 days. Mice were then harvested, and small intestine was collected for analysis. Adaptation occurred in both SBR groups; however, the SBR/HFD had significantly increased villus height compared to SBR/LD. Reverse transcription-polymerase chain reaction of villus enterocytes showed a marked increase in CD36 expression in the SBR/HFD group compared with SBR/LD mice. While exposure to increased enteral fat alone did not affect villus morphology in sham-operated mice, HFD significantly increased villus growth in the setting of resection-induced adaptation, supporting the clinical utility of enteral fat in augmenting adaptation. Increased expression of CD36 suggests a possible mechanistic role in dietary fat metabolism and villus growth in the setting of short gut syndrome.
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Melendez J, Liu M, Sampson L, Akunuru S, Han X, Vallance J, Witte D, Shroyer N, Zheng Y. Cdc42 coordinates proliferation, polarity, migration, and differentiation of small intestinal epithelial cells in mice. Gastroenterology 2013; 145:808-19. [PMID: 23792201 PMCID: PMC3876942 DOI: 10.1053/j.gastro.2013.06.021] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 06/09/2013] [Accepted: 06/10/2013] [Indexed: 01/09/2023]
Abstract
BACKGROUND & AIMS Cdc42 is a Rho GTPase that regulates diverse cellular functions, including proliferation, differentiation, migration, and polarity. In the intestinal epithelium, a balance among these events maintains homeostasis. We used genetic techniques to investigate the role of Cdc42 in intestinal homeostasis and its mechanisms. METHODS We disrupted Cdc42 specifically in intestinal epithelial cells by creating Cdc42flox/flox-villin-Cre+ and Cdc42flox/flox-Rosa26-CreER+ mice. We collected intestinal and other tissues, and analyzed their cellular, molecular, morphologic, and physiologic features, compared with the respective heterozygous mice. RESULTS In all mutant mice studied, the intestinal epithelium had gross hyperplasia, crypt enlargement, microvilli inclusion, and abnormal epithelial permeability. Cdc42 deficiency resulted in defective Paneth cell differentiation and localization without affecting the differentiation of other cell lineages. In mutant intestinal crypts, proliferating stem and progenitor cells increased, compared with control mice, resulting in increased crypt depth. Cdc42 deficiency increased migration of stem and progenitor cells along the villi, caused a mild defect in the apical junction orientation, and impaired intestinal epithelium polarity, which can contribute to the observed defective intestinal permeability. The intestinal epithelium of the Cdc42flox/flox-villin-Cre+ and Cdc42flox/flox-Rosa26-CreER+ mice appeared similar to that of patients with microvillus inclusion disease. In the digestive track, loss of Cdc42 also resulted in crypt hyperplasia in the colon, but not the stomach. CONCLUSIONS Cdc42 regulates proliferation, polarity, migration, and differentiation of intestinal epithelial cells in mice and maintains intestine epithelial barrier and homeostasis. Defects in Cdc42 signaling could be associated with microvillus inclusion disease.
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Affiliation(s)
- Jaime Melendez
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio,Department of Pharmacy, Faculty of Chemistry, P. Catholic University of Chile, Santiago, Chile
| | - Ming Liu
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Leesa Sampson
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Shailaja Akunuru
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Xiaonan Han
- Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Jefferson Vallance
- Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - David Witte
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Noah Shroyer
- Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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Wang Y, Han G, Chen Y, Wang K, Liu G, Wang R, Xiao H, Li X, Hou C, Shen B, Guo R, Li Y, Chen G. Protective role of tumor necrosis factor (TNF) receptors in chronic intestinal inflammation: TNFR1 ablation boosts systemic inflammatory response. J Transl Med 2013; 93:1024-35. [PMID: 23897411 DOI: 10.1038/labinvest.2013.89] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 12/12/2022] Open
Abstract
Tumor necrosis factor-α (TNF-α) acts as a key factor for the development of inflammatory bowel diseases (IBDs), whose function is known to be mediated by TNF receptor 1 (TNFR1) or TNFR2. However, the precise role of the two receptors in IBD remains poorly understood. Herein, chronic colitis was established by oral administration of dextran sulfate sodium (DSS) in TNFR1 or TNFR2-/- mice. Unexpectedly, TNFR1 or TNFR2 deficiency led to exacerbation of signs of colitis compared with wild-type (WT) counterparts. Of note, TNFR1 ablation rendered significantly increased mortality compared with TNFR2 and WT mice after DSS. Aggravated pathology of colitis in TNFR1-/- or TNFR2-/- mice correlated with elevated colonic expression of proinflammatory cytokines and chemokines. Importantly, ablation of TNFR1 or TNFR2 increased apoptosis of colonic epithelial cells, which might be due to the heightened ratio of Bax/Bcl-2 and increased expression of caspase-8. Intriguingly, despite comparable intensity of intestinal inflammation in TNFR-deficient mice after DSS, systemic inflammatory response (including splenomegaly and myeloid expansion) was augmented dramatically in TNFR1-/- mice, instead of TNFR2-/- mice. Granulocyte-macrophage colony-stimulating factor (GMCSF) was identified as a key mediator in this process, as neutralization of GMCSF dampened peripheral inflammatory reaction and reduced mortality in TNFR1-/- mice. These data suggest that signaling via TNFR1 or TNFR2 has a protective role in chronic intestinal inflammation, and that lacking TNFR1 augments systemic inflammatory response in GMCSF-dependent manner.
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Affiliation(s)
- Yi Wang
- Department of Immunology, Institute of Basic Medical Sciences, Beijing, China
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Park DS, Tompkins RO, Liu F, Zhang J, Phoon CKL, Zavadil J, Fishman GI. Pocket proteins critically regulate cell cycle exit of the trabecular myocardium and the ventricular conduction system. Biol Open 2013; 2:968-78. [PMID: 24143284 PMCID: PMC3773344 DOI: 10.1242/bio.20135785] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 06/20/2013] [Indexed: 01/22/2023] Open
Abstract
During development, the ventricular conduction system (VCS) arises from the trabecular or spongy myocardium. VCS and trabecular myocytes proliferate at a significantly slower rate than compact zone myocardial cells, establishing a transmural cell cycle gradient. The molecular determinants of VCS/trabecular myocyte cell cycle arrest are not known. Given the importance of pocket proteins (Rb, p107 and p130) in mediating G0/G1 arrest in many cell types, we examined the role of this gene family in regulating cell cycle exit of the trabecular myocardium and ventricular conduction system. Using a combinatorial knockout strategy, we found that graded loss of pocket proteins results in a spectrum of heart and lung defects. p107/p130 double knockout (dKO) hearts manifest dysregulated proliferation within the compact myocardium and trabecular bases, while the remaining trabecular region cell cycle exits normally. Consequently, dKO hearts exhibit defective cardiac compaction, septal hyperplasia and biventricular outflow tract obstruction, while the VCS appears relatively normal. Loss of all three pocket proteins (3KO) is necessary to completely disrupt the transmural cell cycle gradient. 3KO hearts exhibit massive overgrowth of the trabecular myocardium and ventricular conduction system, which leads to fetal heart failure and death. Hearts carrying a single pocket protein allele are able to maintain the transmural cell cycle gradient. These results demonstrate the exquisite sensitivity of trabecular and conduction myocytes to pocket protein function during ventricular chamber development.
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Affiliation(s)
- David S Park
- Leon H. Charney Division of Cardiology, New York University School of Medicine , New York, NY 10016 , USA ; Heart Rhythm Center, New York University School of Medicine , New York, NY 10016 , USA
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Choi P, Guo J, Erwin CR, Warner BW. IGF-2 mediates intestinal mucosal hyperplasia in retinoblastoma protein (Rb)-deficient mice. J Pediatr Surg 2013; 48:1340-7. [PMID: 23845628 PMCID: PMC3885982 DOI: 10.1016/j.jpedsurg.2013.03.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 03/08/2013] [Indexed: 01/22/2023]
Abstract
PURPOSE We have previously demonstrated a hyperplastic phenotype when Rb expression was disrupted within the intestinal epithelium. These findings mimic resection-induced adaptation suggesting a possible mechanistic role for Rb during adaptation. The purpose of the present study was to elucidate a mechanism for how Rb deficiency induces intestinal hyperplasia. METHODS Enterocytes isolated from intestine-specific Rb knockout mice (Rb-IKO) underwent a microarray to elucidate their gene expression profile. IGF2 expression was significantly elevated, which was subsequently confirmed by RT-PCR and in situ mRNA hybridization. Mice with deficient expression of IGF2 or its receptor IGF1R were therefore crossed with Rb-IKO mice to determine the significance of IGF2 in mediating the Rb-IKO intestinal phenotype. RESULTS Expression of IGF2 was significantly elevated in villus enterocytes of Rb-IKO mice. The mucosal hyperplasia in Rb-IKO mice was reversed when either IGF2 or IGF1R expression was genetically disrupted in Rb-IKO mice. CONCLUSION IGF-2 expression is significantly elevated in villus enterocytes and is required for the hyperplastic intestinal mucosal phenotype of Rb-IKO mice. The trophic effects of IGF2 require intact IGF1R signaling within the intestinal epithelium. These findings reveal novel regulatory roles for Rb in expanding intestinal mucosal surface area.
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Affiliation(s)
| | | | | | - Brad W. Warner
- Corresponding author. Tel.: +1 314 454 6022; fax: +1 314 454 2442. (B.W. Warner)
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Rowland KJ, Yao J, Wang L, Erwin CR, Maslov KI, Wang LV, Warner BW. Up-regulation of hypoxia-inducible factor 1 alpha and hemodynamic responses following massive small bowel resection. J Pediatr Surg 2013; 48:1330-9. [PMID: 23845627 PMCID: PMC3755458 DOI: 10.1016/j.jpedsurg.2013.03.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/08/2013] [Indexed: 02/07/2023]
Abstract
PURPOSE Massive small bowel resection (SBR) results in an adaptive response within the remnant bowel. We have previously shown an immediate reduction in intestinal blood flow and oxygen saturation (sO2) after SBR. We therefore sought to determine the duration of resection-induced intestinal hypoxia and expression of hypoxia-inducible factors (HIFs) following SBR. METHODS C57B6 mice were subjected to 50% proximal SBR or a sham procedure. Photoacoustic microscopy (PAM) was used to measure blood flow and sO2 on postoperative days (PODs) 1, 3, and 7. Ileal tissue was harvested 6h postoperatively and on PODs 1 and 2, and HIF1α, HIF2α, and VEGF mRNA expression were assessed via RT-PCR. A p value of less than 0.05 was considered significant. RESULTS Following SBR, reduction in intestinal blood flow persists for 24h and is followed with hyperemia by POD 3. The immediate reduction in venous sO2 and increased tissue oxygen utilization continued through POD 7. Enhanced expression of HIF1α was demonstrated 6h following SBR. CONCLUSION Massive SBR results in an immediate relative hypoxic state within the remnant bowel with early enhanced expression of HIF1α. On POD 7, increased tissue oxygen extraction and elevated blood flow persist in the adapting intestine.
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Affiliation(s)
- Kathryn J. Rowland
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lidai Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Christopher R. Erwin
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Konstantin I. Maslov
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lihong V. Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA,Corresponding author. Tel.: +1 314 454 6022; fax: +1 314 454 2442. (L.V. Wang), (B.W. Warner)
| | - Brad W. Warner
- Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA,Corresponding author. Tel.: +1 314 454 6022; fax: +1 314 454 2442. (L.V. Wang), (B.W. Warner)
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Abstract
Adaptation is an important compensatory response to environmental cues resulting in enhanced survival. In the gut, the abrupt loss of intestinal length is characterized by increased rates of enterocyte proliferation and apoptosis and culminates in adaptive villus and crypt growth. In the development of an academic pediatric surgical career, adaptation is also an important compensatory response to survive the ever changing research, clinical, and economic environment. The ability to adapt in both situations is critical for patients and a legacy of pediatric surgical contributions to advance our knowledge of multiple conditions and diseases.
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Wakeman D, Schneider JE, Liu J, Wandu WS, Erwin CR, Guo J, Stappenbeck TS, Warner BW. Deletion of p38-alpha mitogen-activated protein kinase within the intestinal epithelium promotes colon tumorigenesis. Surgery 2012; 152:286-93. [PMID: 22828150 DOI: 10.1016/j.surg.2012.05.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 05/10/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND p38-Alpha mitogen-activated protein kinase (p38-MAPK) is a tumor suppressor often mutated in human cancers, but its specific role in colorectal cancer is not completely understood. Previous studies have found that p38-MAPK activity inhibits epithelial proliferation and promotes apoptosis in the intestine. Therefore, we sought to test the hypothesis that intestinal disruption of p38-MAPK would lead to increased tumorigenesis in the colon. METHODS p38-MAPK was deleted in mice within the intestinal epithelium using a tamoxifen-inducible Cre system under control of the villin promoter [villin-Cre ERT2(+), MAPK14(f/f)]. An azoxymethane and dextran sodium sulfate protocol was used to drive intestinal tumor development. Tumor measurements were made using computer software from photographs of excised colon specimens. RESULTS The number of mice that developed tumors was not statistically different when comparing wild-type mice (7/14) to inducible, intestine epithelial-deleted p38-MAPK (9/11) mice after azoxymethane/dextran sodium sulfate treatment (P = .21). However, the epithelial-deleted p38-MAPK mice developed significantly more tumors (3.7 vs 1.1; P = .008) and nearly 4 times the total tumor burden as wild-type mice (17.4 vs 4.8 mm(2); P = .03). Wild-type and epithelial-deleted p38-MAPK groups demonstrated a similar degree of colon inflammation. CONCLUSION Deletion of p38-MAPK within the colonic mucosa leads to a hyperplastic state promoting greater tumor development. Because the severity of colitis was not augmented in mice with p38-MAPK deficiency, tumor development is likely mediated by impaired cell cycle regulation within the colonic epithelium. Manipulation of p38-MAPK activity may provide a novel treatment and/or prevention strategy in the management of colorectal cancer, particularly in the setting of inflammatory bowel disease.
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Affiliation(s)
- Derek Wakeman
- Division of Pediatric Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO, USA
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Rowland KJ, McMellen ME, Wakeman D, Wandu WS, Erwin CR, Warner BW. Enterocyte expression of epidermal growth factor receptor is not required for intestinal adaptation in response to massive small bowel resection. J Pediatr Surg 2012; 47:1748-53. [PMID: 22974617 PMCID: PMC3443391 DOI: 10.1016/j.jpedsurg.2012.03.089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 03/06/2012] [Indexed: 02/07/2023]
Abstract
PURPOSE Intestinal adaptation after massive small bowel resection (SBR) permits improved absorption of enteral nutrition despite significant loss of bowel length. Epidermal growth factor (EGF) and its receptor (EGFR) have previously been established to play major roles in the pathogenesis of adaptation. This study tested the hypothesis that EGFR signaling within the epithelial cell compartment (enterocytes) is required for intestinal adaptation. METHODS We developed a tamoxifen-inducible Villin-Cre/LoxP recombinant system for enterocyte-directed EGFR deletion using EGFR-floxed mice. Epidermal growth factor receptor-null mice and wild-type littermates underwent either 50% proximal SBR or sham operation. Ileal tissue was harvested on postoperative day 7. To assess for adaptation, villus height and crypt depth as well as rates of crypt cell proliferation and apoptosis were measured. RESULTS Adaptation after SBR occurred normally, as demonstrated by significant increases in villus height, crypt depth, and crypt proliferative and apoptotic index in both the wild-type and EGFR-null mice. CONCLUSION Enterocyte EGFR expression is not required for the adaptation response to massive SBR. This novel finding suggests that enterocyte proliferation during adaptation is regulated by EGFR signaling in cells other than enterocytes, perhaps within the mesenchymal cell compartment of the bowel wall via factor(s) that are presently unknown.
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Affiliation(s)
| | | | | | | | | | - Brad W. Warner
- Correspondence: Brad W. Warner, M.D., St. Louis Children's Hospital, One Children's Place; Suite 5S40, St. Louis MO 63110, (314) 454-6022 - Phone, (314) 454-2442 – Fax,
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Léguillier T, Vandormael-Pournin S, Artus J, Houlard M, Picard C, Bernex F, Robine S, Cohen-Tannoudji M. Omcg1 is critically required for mitosis in rapidly dividing mouse intestinal progenitors and embryonic stem cells. Biol Open 2012; 1:648-57. [PMID: 23213458 PMCID: PMC3507298 DOI: 10.1242/bio.20121248] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Recent studies have shown that factors involved in transcription-coupled mRNA processing are important for the maintenance of genome integrity. How these processes are linked and regulated in vivo remains largely unknown. In this study, we addressed in the mouse model the function of Omcg1, which has been shown to participate in co-transcriptional processes, including splicing and transcription-coupled repair. Using inducible mouse models, we found that Omcg1 is most critically required in intestinal progenitors. In absence of OMCG1, proliferating intestinal epithelial cells underwent abnormal mitosis followed by apoptotic cell death. As a consequence, the crypt proliferative compartment of the small intestine was quickly and totally abrogated leading to the rapid death of the mice. Lack of OMCG1 in embryonic stem cells led to a similar cellular phenotype, with multiple mitotic defects and rapid cell death. We showed that mutant intestinal progenitors and embryonic stem cells exhibited a reduced cell cycle arrest following irradiation, suggesting that mitotic defects may be consecutive to M phase entry with unrepaired DNA damages. These findings unravel a crucial role for pre-mRNA processing in the homeostasis of the small intestine and point to a major role of OMCG1 in the maintenance of genome integrity.
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Affiliation(s)
- Teddy Léguillier
- Institut Pasteur, Unité de Génétique Fonctionnelle de la Souris, Département de Biologie du Développement , 25 rue du docteur Roux, F-75015 Paris , France ; CNRS URA 2578, F-75015 Paris , France
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Wakeman D, Guo J, Santos JA, Wandu WS, Schneider JE, McMellen ME, Leinicke JA, Erwin CR, Warner BW. p38 MAPK regulates Bax activity and apoptosis in enterocytes at baseline and after intestinal resection. Am J Physiol Gastrointest Liver Physiol 2012; 302:G997-1005. [PMID: 22383494 PMCID: PMC3362074 DOI: 10.1152/ajpgi.00485.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 02/27/2012] [Indexed: 01/31/2023]
Abstract
Increased apoptosis in crypt enterocytes is a key feature of intestinal adaptation following massive small bowel resection (SBR). Expression of the proapoptotic factor Bax has been shown to be required for resection-induced apoptosis. It has also been demonstrated that p38-α MAPK (p38) is necessary for Bax activation and apoptosis in vitro. The present studies were designed to test the hypothesis that p38 is a key regulator of Bax activation during adaptation after SBR in vivo. Enterocyte expression of p38 was deleted by tamoxifen administration to activate villin-Cre in adult mice with a floxed Mapk14 (p38-α) gene. Proximal 50% SBR or sham operations were performed on wild-type (WT) and p38 intestinal knockout (p38-IKO) mice under isoflurane anesthesia. Mice were killed 3 or 7 days after operation, and adaptation was analyzed by measuring intestinal morphology, proliferation, and apoptosis. Bax activity was quantified by immunoprecipitation, followed by Western blotting. After SBR, p38-IKO mice had deeper crypts, longer villi, and accelerated proliferation compared with WT controls. Rates of crypt apoptosis were significantly lower in p38-IKO mice, both at baseline and after SBR. Levels of activated Bax were twofold higher in WT mice after SBR relative to sham. In contrast, activated Bax levels were reduced by 67% in mice after p38 MAPK deletion. Deleted p38 expression within the intestinal epithelium leads to enhanced adaptation and reduced levels of enterocyte apoptosis after massive intestinal resection. p38-regulated Bax activation appears to be an important mechanism underlying resection-induced apoptosis.
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Affiliation(s)
- Derek Wakeman
- Department of Surgery, Division of Pediatric Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Belaguli NS, Zhang M, Garcia AH, Berger DH. PIAS1 is a GATA4 SUMO ligase that regulates GATA4-dependent intestinal promoters independent of SUMO ligase activity and GATA4 sumoylation. PLoS One 2012; 7:e35717. [PMID: 22539995 PMCID: PMC3334497 DOI: 10.1371/journal.pone.0035717] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 03/20/2012] [Indexed: 01/12/2023] Open
Abstract
GATA4 confers cell type-specific gene expression on genes expressed in cardiovascular, gastro-intestinal, endocrine and neuronal tissues by interacting with various ubiquitous and cell-type-restricted transcriptional regulators. By using yeast two-hybrid screening approach, we have identified PIAS1 as an intestine-expressed GATA4 interacting protein. The physical interaction between GATA4 and PIAS1 was confirmed in mammalian cells by coimmunoprecipitation and two-hybrid analysis. The interacting domains were mapped to the second zinc finger and the adjacent C-terminal basic region of GATA4 and the RING finger and the adjoining C-terminal 60 amino acids of PIAS1. PIAS1 and GATA4 synergistically activated IFABP and SI promoters but not LPH promoters suggesting that PIAS1 differentially activates GATA4 targeted promoters. In primary murine enterocytes PIAS1 was recruited to the GATA4-regulated IFABP promoter. PIAS1 promoted SUMO-1 modification of GATA4 on lysine 366. However, sumoylation was not required for the nuclear localization and stability of GATA4. Further, neither GATA4 sumoylation nor the SUMO ligase activity of PIAS1 was required for coactivation of IFABP promoter by GATA4 and PIAS1. Together, our results demonstrate that PIAS1 is a SUMO ligase for GATA4 that differentially regulates GATA4 transcriptional activity independent of SUMO ligase activity and GATA4 sumoylation.
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Affiliation(s)
- Narasimhaswamy S. Belaguli
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey VA Medical Center, Houston, Texas, United States of America
- * E-mail: (NSB); (DHB)
| | - Mao Zhang
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey VA Medical Center, Houston, Texas, United States of America
| | - Andres-Hernandez Garcia
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey VA Medical Center, Houston, Texas, United States of America
| | - David H. Berger
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey VA Medical Center, Houston, Texas, United States of America
- * E-mail: (NSB); (DHB)
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Leinicke JA, Longshore S, Wakeman D, Guo J, Warner BW. Regulation of retinoblastoma protein (Rb) by p21 is critical for adaptation to massive small bowel resection. J Gastrointest Surg 2012; 16:148-55; discussion 155. [PMID: 22042567 PMCID: PMC3779625 DOI: 10.1007/s11605-011-1747-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 10/13/2011] [Indexed: 01/31/2023]
Abstract
BACKGROUND Adaptation following massive intestinal loss is characterized by increased villus height and crypt depth. Previously, we demonstrated that p21-null mice do not adapt after small bowel resection (SBR). As retinoblastoma protein (Rb) levels are elevated in p21-null crypt cells, we first sought to determine whether Rb is required for normal adaptation. Next, we tested whether Rb expression is responsible for blocked adaptation in p21-nulls. METHODS Genetically manipulated mice and wild-type (WT) littermates underwent either 50% SBR or sham operation. The intestine was harvested at 3, 7, or 28 days later and intestinal adaptation was evaluated. Enterocytes were isolated and protein levels evaluated by Western blot and quantified by optical density. RESULTS Rb-null mice demonstrated increased villus height, crypt depth, and proliferative rate at baseline, but there was no further increase following SBR. Deletion of one Rb allele lowered Rb expression and restored resection-induced adaptation responses in p21-null mice. CONCLUSION Rb is specifically required for resection-induced adaptation. Restoration of adaptation in p21-null mice by lowering Rb expression suggests a crucial mechanistic role for Rb in the regulation of intestinal adaptation by p21.
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Affiliation(s)
- Jennifer A. Leinicke
- Division of Pediatric Surgery, St. Louis Children’s Hospital, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Shannon Longshore
- Division of Pediatric Surgery, St. Louis Children’s Hospital, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Derek Wakeman
- Division of Pediatric Surgery, St. Louis Children’s Hospital, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Jun Guo
- Division of Pediatric Surgery, St. Louis Children’s Hospital, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Brad W. Warner
- Division of Pediatric Surgery, St. Louis Children’s Hospital, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, USA. Division of Pediatric Surgery, St. Louis Children’s Hospital, One Children’s Place, Suite 5s40, St. Louis, MO 63110, USA
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Hadjistilianou T, Giglioni S, Micheli L, Vannoni D, Brogi E, Cevenini G, Cortelazzo A, De Francesco S, Menicacci F, Leoncini R. Analysis of aqueous humour proteins in patients with retinoblastoma. Clin Exp Ophthalmol 2011; 40:e8-e15. [PMID: 22003840 DOI: 10.1111/j.1442-9071.2011.02711.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND To investigate aqueous humour protein composition from retinoblastoma patients. DESIGN Prospective, hospital-based study. PARTICIPANTS Eighteen retinoblastoma patients (Reese-Ellsworth stage V or ABC classification group E RB) undergoing ocular enucleation, and 10 normal subjects undergoing cataract surgery. Five of 18 patients presented with associated secondary glaucoma whereas 13 had no secondary glaucoma; 5 of 13 patients with no secondary glaucoma received chemotherapeutical treatment with melphalan. METHODS Aqueous humour samples were collected by limbal paracentesis of the anterior chamber after ocular enucleation in patients and after the stab peripheral corneal incision in controls. Total protein concentration according to Bradford method and sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the samples were performed. MAIN OUTCOME MEASURE Aqueous humour protein concentration. RESULTS Aqueous humour protein concentration was significantly higher in retinoblastoma patients than controls (P < 0.01); patients with secondary glaucoma presented the highest values (P < 0.05 vs. controls); patients treated with melphalan presented a significant decrease (P < 0.01) versus non-treated; controls did not significantly differ from treated patients. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis pattern in retinoblastoma patients who did not receive any treatment was very different either from treated or from controls. CONCLUSION This study represents a preliminary step towards a more accurate two dimensional electrophoresis (2DE) pattern, which will be combined with mass spectrometry analysis to clarify the potential role of specific proteins in tumour development and progression; although these results suggest that aqueous humour protein pattern in retinoblastoma is characteristic, several aspects of the study are still under investigation.
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